Semiconductor processing boat design with pressure sensor

ABSTRACT

Presented herein is a device processing boat comprising a base and at least one unit retainer disposed in the base. The device further comprises a cover having at least one recess configured to accept and retain at least one unit. The at least one recess is aligned over, and configured to hold the at least one unit over, at least a portion of the at least one unit retainer. The cover is retained to the device processing boat by the at least one unit retainer. At least one pressure sensor having at least one sensel is disposed in the base. The sensel is configured to sense a clamping force applied by the cover to the at least one unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.14/159,106, filed on 20 Jan. 2014, entitled “Semiconductor ProcessingBoat Design with Pressure Sensor,” which application is herebyincorporated by reference.

BACKGROUND

Semiconductor devices are used in a variety of electronic applications,such as, for example, personal computers, cell phones, digital cameras,and other electronic equipment. The semiconductor industry continues toimprove the integration density of various electronic components (e.g.,transistors, diodes, resistors, capacitors, etc.) by continualreductions in minimum feature size, which allow more components to beintegrated into a given area. In some devices, multiple dies are stackedvertically to reduce the footprint of a device package and permit dieswith different processing technologies to be interconnected. Thevertically stacked devices are electrically connected to each other toprovide signal communication between devices, and the electricalconnections may be formed from solder, wire bonds, lands, vias, pillars,studs, or the like.

In some devices, multiple devices may be joined during processing of thedevices to permit rapid throughput of the packages and to take advantageof the processing capabilities of the fabrication equipment. Dies,packages, chips, devices, or the like maybe stacked in precise alignmentand subsequently electrically connected to each other.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures.Corresponding numerals and symbols in the different figures generallyrefer to corresponding parts unless otherwise indicated. The figures aredrawn to illustrate the relevant aspects of the embodiments and itshould be noted that, in accordance with the standard practice in theindustry, various features are not drawn to scale. In fact, thedimensions of the various features may be arbitrarily increased orreduced for clarity of discussion.

FIGS. 1A-1C and 2A-2B are top views and cross-sectional viewsillustrating a boat with retainers in accordance with some embodiments;

FIGS. 3A-3D are top views illustrating boats with alternative retainerarrangements according to some embodiments;

FIGS. 4 and 5A-5B illustrate cross-sectional views aligning units andmounting packages on the units using a cover and according to someembodiments;

FIGS. 6A-6B illustrate cross-sectional views of boats with pressuresensors according to some embodiments;

FIG. 7 illustrates a system for reading boat pressure sensors accordingto some embodiments; and

FIG. 8 is a flow diagram illustrating a method for mounting a package ona unit according to some embodiments.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the provided subjectmatter. Specific examples of components and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

Units such as dies, chips, substrates, or other structures used insemiconductor production may be processed in controlled environments bysubjecting the units to processing variables that may cause physicalchanges or deformations in the unit. In some instances, back-end-of-lineprocessing may be used to mount a package, die, device, or otherstructure on a unit using solder balls or other heat activatedconnecting material, or by wire bonding, welding, or the like. In someembodiments, solder is reflowed by heating the unit and package to meltthe solder connection before permitting the solder to solidify and forma solid connection between the unit and the package.

In order to precisely align the unit and package before and duringreflow, the units are aligned on a boat, and a cover is placed over theunits to maintain the units in a predetermined location before andduring reflow. As described in greater detail below, the cover isretained to the boat with one or more retainers, and packages aremounted to the units through openings in the cover. The pressure atwhich the units are held to the boat may be measured using pressuresensors on the boat to verify that a unit maintained a desired shape andlocation before, during and after reflow or heat treating.

FIG. 1A is a top view of a device processing boat 100 with retainers102, 108 according to some embodiments. FIGS. 1B and 1C arecross-sectional views of the boat 100 showing the retainers 102, 108 inthe base 104 according to some embodiments. The boat 100 has a base 104with border retainers 102 around the edge of the base 104. The base 104is a substrate, platform or surface for holding a unit duringprocessing. In some embodiments, the base 104 is a wafer, substrate,glass carrier, ceramic, or the like.

The border retainers 102 are arranged around or bordering an interiorregion where the units 106 are located during processing. Unit retainers108 are arranged in the interior regions of the boat 100 and are insidethe border retainers 102. The unit retainers 108 and the borderretainers 102 are, in some embodiments, magnets embedded in the base104. The use of a magnet for the retainers 102, 108 permits a cover(see, e.g., FIGS. 4-5 and 6A-6B) to be placed over the boat 100 to holdthe units 106 flat on the top surface of the base 104 during processing.The units 106 are also retained in unit areas of the base 104 by thecover so that the units 106 are in a known and predetermined position inrelation to the boat 100, and subsequent processing is more precise. Itshould be noted that the retainers 102, 108 are not limited solely tobeing formed from a magnet. In other embodiments the retainers 102, 108may be clips, adhesives, snaps or another structure that holds the coversecurely to the base.

In an embodiment, the unit retainers 108 are disposed in the base 104and touch or extend into, the regions where the units 106 are placed.Thus, when the units are aligned and placed on the boat 100, each unit106 has at least one unit retainer 108 under the unit 106.

In an embodiment where the unit retainers 108 are magnets, the unitretainers 108 have portions extending from under the units 106 past theedges of the units 106. In some embodiments, at least a portion of eachof the unit retainers 108 is uncovered by the units 106. This permitsthe cover to align over a part of the unit retainer 108 without the unitinterfering or coming between the unit retainer 108 and cover. Thisresults in greater clamping force on the individual units 106 to preventwarping or deformation of the units 106 during processing. In otherembodiments, the units 106 may be part of a continuous workpiece, suchas a wafer or strip of units, or the unit 106 may be a larger structurespanning more than one unit retainer 108. In such embodiments, the unitretainers 108 may be completely disposed under the unit 106 orworkpiece.

In some embodiments, the magnets for the unit retainer 108 are rareearth magnets such as samarium cobalt (SmCo), neodymium iron boron(NdFeB) or the like, ceramic magnets such as strontium ferrite (SrFe),alnico magnets, or other magnetic materials that can withstand the heatand environmental conditions associated with processing the units 106.Additionally, the magnets will be powerful enough to retain the coveragainst the surface of the base 104 and unit retainers 108 duringprocessing to prevent warping or deformation of the units 106. Themagnetic field strength required by the magnets used for the unitretainers 108 varies based on the area of the unit retainers 108disposed underneath the units 106, and the thickness and magneticpermittivity of the units. The magnetic field of the unit retainer 108attracts the cover through the units 106, however, the presence of theunit 106 may attenuate the magnetic field passing through the unit 106.

FIG. 1B is a cross-sectional view showing an embodiment of the sectionAA in FIG. 1A. In such an embodiment, the unit retainers 108 and borderretainers 102 are embedded underneath the top surface of the base 104A.In an embodiment, the retainers 102 and 108 in this embodiment areexposed at the bottom surface of the boat, however, the placement of theretainers 102 and 108 is not limited to such location. For example, insome embodiments, the retainers 102 and 108 are disposed in the centerof the base 104 so that they are between but spaced apart from both thetop base surface 104A and the bottom surface 104B of the base 104.

FIG. 1C is a cross-sectional view showing another embodiment of thesection AA in FIG. 1A. In such an embedment, the unit retainers 108 andborder retainers 102 are embedded in the base 104 and have a surfaceexposed at the top surface of the base 104A.

FIG. 2A is a top view diagram illustrating a boat 100 with units 106formed as strips according to some embodiments. It should be understoodthat the boat 100 disclosed herein is not limited to handling individualsingulated units 106, but may also accept any package form that permitsthe cover to be attached with a magnet may be used. For example, theunits 106 may be singulated, or may be formed as multiple or singleunits 106 in a strip or as units 106 disposed on a single workpiece 302,or in a grid arrangement, as on a wafer.

The units 106 may be part of a workpiece that was, for example, cut froma wafer, or the units 106 may be mounted to a carrier for processing, orto a PCB, package, or other structure. In the illustrated embodiment,the unit retainers 108 are disposed under the units 106, and one or moreunit retainers may extend under, or be completely under, the units 106.Such an arrangement permits the unit retainers 108 to attract the coverand hold the cover onto the strip with units 106 to align the units 106.

FIG. 2A is a top view of a boat 100 with strip-type unit retainers 108according to some embodiments. FIG. 2B is a cross-sectional view of theboat 100 showing the strip-type unit retainers 108 in the base 104according to some embodiments. In an embodiment, the boat 100 has unitretainers 108 that extend under multiple units 106. The unit retainers108 have portions extending from under the units 106 past opposite edgesof the units 106 so that a portion of the unit retainers 108 areuncovered by the units 106. Thus, in such an embodiment, a single unitretainer 108 has a surface exposed at opposing sides of a single unit106. Additionally, the one unit retainer 108 as shown in FIG. 2A is notlimited to extending under multiple units 106 in a single row, and may,in other embodiments, be under a single unit 106 and extend past theedges of that unit 106, or may extend under multiple units 106 inmultiple rows. For example, a unit retainer 108 may extend underadjacent corners of four units 106 in a two-by-two or larger grid.

FIG. 3A is a top view illustrating a boat 100 with unit retainers 108extending under two units 106 according to some embodiments. In such anembodiment, the units 106 are spaced apart and the unit retainer 108extends between two adjacent units 106, with different portions of theunit retainer 108 under each of the units 106. A center portion of theunit retainer 108 is exposed between the adjacent units 106.

FIG. 3B is a top view diagram illustrating a boat 100 with units 106having multiple unit retainers 108 in a unit area according to someembodiments. In such an embodiment, each unit 106 may have two or moreunit retainers 108 extending thereunder. The unit retainers 108 may eachextend under a single unit 106, or may extend under multiple units, asillustrated in FIG. 3A.

FIG. 3C is a top view of a boat 100 with strip-type unit retainers 108according to some embodiments. In an embodiment, the boat 100 has unitretainers 108 that extend under multiple units 106. The unit retainers108 have portions extending from under the units 106 past opposite edgesof the units 106 so that a portion of the unit retainers 108 areuncovered by the units 106. Thus, in such an embodiment, a single unitretainer 108 has a surface exposed at opposing sides of a single unit106 and extending under the unit 106. Additionally, the one unitretainer 108 as shown in FIG. 3C is not limited to extending undermultiple units 106 in a single row, and may, in other embodiments, beunder a single unit 106 and extend past the edges of that unit 106, ormay extend under multiple units 106 in multiple rows. For example, aunit retainer 108 may extend under adjacent corners of four units 106 ina two-by-two or larger grid.

FIG. 3D is a top view diagram illustrating a boat 100 with units 106disposed in grids on workpieces 302 according to some embodiments. Insuch an embodiment the units 106 are disposed in a one ortwo-dimensional array or grid on a workpiece 302. For example, the units106 may be part of a wafer, or may be mounted on a carrier, package orthe like as described above with respect to FIG. 3C. The unit retainer108 may be covered by the workpiece 302, and may lie under one or moreunits 106.

In an embodiment, the cover is formed to have surfaces that abut theunits 106 and align the individual units 106, and in other embodiments,the cover may have surfaces that abut the workpiece 302 to align theworkpiece 302, with the assumption that the units 106 are properlyaligned on the workpiece 302, and that aligning the workpiece 302 withthe cover will align the units 106 also.

FIG. 4 is a cross-sectional view illustrating placement of a cover 402over the units 106 according to some embodiments. The cover 402 retainsand aligns units 106. The cover has recesses in the bottom that acceptthe units 106. A cover sidewall 402A in the recess abuts the side of theunit 106 to hold the unit 106 in alignment, and a portion of the cover402 overlies the unit 106 to maintain the unit 106 in contact with theboat 100. The unit retainer 108 clamps the cover 402 onto the units 106,providing the clamping force that keeps the cover 402 against the topsurface of the boat 100. In an embodiment, one or more alignment pins(not shown here for clarity) may be disposed in the top surface of theboat 100, or in the bottom surface of the cover 402, with acorresponding opening in the opposing member, permitting accuratehorizontal alignment of the cover 402 to the boat 100.

It has been discovered that having at least a portion of the unitretainers 108 exposed or extending past the edges of the units 106 givessuperior cover 402 clamping force. Additionally, the unit retainer 108underlying, or having no lateral spacing apart from the respective unit106, provides clamping of the cover in the region directly abutting theunits 106 and improves alignment and deformation control over the units106 during processing. Thus, the unit retainers 108 are arranged so thatthey are immediately laterally adjacent to, or extend under, the units106 when the units are aligned by the cover 402 when the cover 402 isattached to the boat 100.

In an embodiment where the unit retainers 108 are magnets, the magnetswill be powerful enough to exert between about 450 gf (grams of force)and about 1000 gf on each unit. Additionally, in such an embodiment, thecover 402 is made from a ferromagnetic material such as iron, cobalt,steel, nickel, alloys of the same or other material that are attractedto a magnetic field. In some embodiments, the cover 402 is formed from asuitable material resistant to the processing environment and hasferromagnetic inserts that attach to the unit retainers 108 and borderretainers 102 to align and clamp the cover 402 to the boat 100. Thus,the cover 402 is attached to the boat 100 by the interactions of themagnets forming the unit retainers 108 and the material of the cover402.

Furthermore, while the cover 402 is shown contacting the top surface ofthe boat 100 and the unit retainers 108, the cover 402 is notnecessarily limited to such an embodiment. In an embodiment, the cover402 may have a portion contacting and retaining the units 106, and maynot extend all the way to the surface of the boat 100. In such anembodiment, retainer pins may align the cover 402 with the boat 100, andthe cover 402 may be spaced apart from the top surface of the boat 100while unit retainers 108 attract and attach the cover 402 to provideclamping force to the cover 402 and units 106. This embodiment may bewhere the unit retainers 108 are magnets, for example, or where the unitretainers 108 are clamps, latches, or the like. Additionally, the covermay be formed with recesses for a workpiece 302 so that units 106 on acarrier, wafer, strip or the like may be accurately clamped to the boat100.

In some embodiments, the cover 402 has openings 404 over each of theunits 106. The openings 404 extend from the top surface of the cover 402to the recesses. The top surface of each unit 106 is exposed through thecover 402 permitting access to the units 106 while clamped, for example,to permit mounting of devices, packages, dies, or the like to the topsurface of the units 106.

FIG. 5A is a cross-sectional view illustrating mounting of top packages502 on clamped units 106 according to some embodiments. One or more toppackages 502 are applied to each of the units 106 through the openings404 in the cover 402. Connectors 504 are brought into contact with theunits 106, and the connectors 504 are affixed to the units 106. In anembodiment, the connectors 504 are solder balls, solder bumps or thelike, and the connectors 504 are activated or affixed to the units byheating the processing environment and the connectors 504 above themelting point of the connector solder material to reflow the solder. Thecover 402 retains the units 106 against the surface of the boat 100 andin the unit areas during reflow. This prevents the units 106 fromshifting out of the unit areas and becoming misaligned with the toppackages 502 due to warping or shifting of the units 106 due to the heatof the reflow process.

FIG. 5B is a cross-sectional view illustrating mounting multiple toppackage 502 to a unit 106 according to some embodiments. In suchembodiments, the cover 402 has multiple openings 404 over a single unit,and one or top packages are mounted by way of connectors 504 to theunit. For example, a large unit 106 such as a processor or the like mayhave top packages 502 such as memory dies, communications dies, or otherauxiliary packages mounted thereon. In an alternative embodiment,multiple units are disposed in a single workpiece, such as a wafer or ona carrier or the like. Each unit 106 on the workpiece will then have oneor more openings 404 over the unit 106 through which the top packages502 are mounted.

FIGS. 6A-6B illustrate cross-sectional views of boats 100 with pressuresensors according to some embodiments. The pressure sensors may have oneor more pressure sensitive areas called sensels 602, where an individualpressure may be measured. Thus, a single sensor 602 may measure pressurein one or more regions on the sensor by reading the individual sensels602. One or more sensels 602 are disposed in or on the base 104 andextend under the units 106. In an embodiment shown in FIG. 6A, each unit106 is disposed over an individual sensor 602. In such an embodiment,the sensels read the pressure of a single unit 106 or of the cover 402around a single unit 106. In another embodiment shown in FIG. 6B, units106 are disposed over a single sensel 602. In such an embodiment, asingle sensor with multiple sensels 602 may sense the pressure appliedto each unit 106 or to the cover 402. In another embodiment, the sensor602 may have a single pressure sensing sensel, and multiple units may bedisposed over the single sensel 602, with the total pressure on all theunits 106 or the pressure on the cover 402 as a whole measured by thesensor 602.

In an embodiment, the pressure sensor has one or more piezoelectricelements forming the individual sensels 602, with pressure on the sensel602 indicated by a voltage value that is read by a sensor readingcomputer system. In other embodiments, the sensel 602 may be anothertype of pressure sensing structure.

FIG. 7 is a diagram illustrating a device processing system 700 forreading pressure sensors 602 on a boat 100A, 100B according to someembodiments. A sensor reading computer system 702 having a processor andnonvolatile memory has software stored on a nontangible medium, thesoftware for reading the pressures indicated by pressure sensors on oneor more boats 100A, 100B. In an embodiment, the sensor reading computersystem 702 is connected to sensels 602 on a first boat 100A havingmultiple units 106 each disposed over an individual sensel 602. Thesensor reading computer system 702 takes pressure readings before,during and after reflow to ensure that the pressure of each unit 106 onthe boat does not fall outside a predetermined or optimal range. Thus,the individual sensels 602 measuring the pressure of the individualunits 106 can determine if each individual unit 106 was maintained in aproper and accurate alignment during attachment of the top package 502and reflow of the connector 504. In another embodiment, the sensorreading computer system 702 is connected to multiple sensels 602disposed under a single unit 106. In such an embodiment, pressurereadings from individual sensels 602 can determine if specific areas ofa unit 106 were maintained in proper alignment during attachment of thetop package 502 and reflow of the connectors 504. For example, readingsfrom one or more sensels 602 that vary during reflow may indicate thatthe unit 106 warped during reflow. Additionally, in other embodiments,the sensor reading computer system 702 is connected to multiple boats100 with different sensel arrangements.

FIG. 8 is a flow diagram illustrating a method 800 for mounting apackage on a unit according to some embodiments. Initially, in block802, units are placed on the boat and aligned with the unit retainers sothat each unit covers a portion of a unit retainer, or directly abuts aregion over a unit retainer. The cover is placed over the units in block804, with the cover being retained by the border retainers and unitretainers. The units are held in place on the boat by the cover.Packages are mounted on the units in block 806, and the connectorsconnecting the package to the units are activated, for example byreflowing solder material of the connectors. Pressure readings are takenin block 808 either before, during or after activating the connectors,or multiple pressure readings are taken at combination of theaforementioned periods. The pressure readings are verified in block 810.

A device according to embodiments comprises a device processing boatcomprising a base and at least one unit retainer disposed in the base.The device further comprises a cover having at least one recessconfigured to accept and retain at least one unit, the at least onerecess aligned over, and configured to hold the at least one unit over,at least a portion of the at least one unit retainer. The cover isretained to the device processing boat by the at least one unitretainer. The at least one unit retainer is a magnet, and the cover hasat least one cover portion formed from a material that is attracted to amagnetic field, the at least one cover portion corresponding to at leasta portion of the at least one unit retainer. A plurality of borderretainers is disposed in the base, and the cover is configured to alignover and be retained by the plurality of border retainers. In anembodiment, the at least one recess comprises two or more recesses andwherein the at least one unit retainer extends under at least two of thetwo or more recesses. In an embodiment, the at least one unit retainercomprises two or more unit retainers, and wherein at least two of thetwo or more unit retainers extend under a same one of the two or morerecesses. The cover has an opening over each of the recesses. At leastone pressure sensor having at least one sensel is disposed in the baseand having the sensel configured to sense a clamping force applied bythe cover to the at least one unit. At least one pressure sensorcomprises a plurality of sensels, and the at least one unit comprises aplurality of units. Each of the plurality of sensels is configured tosense the clamping force applied by the cover to a respective one of theplurality of units.

A device processing system according to embodiments comprises at leastone device processing boat, comprising a base and at least one unitretainer disposed in the base and having a portion immediately adjacentto a unit area. At least one pressure sensor is disposed in the base andhas at least one sensel extending into the unit area, the at least onesensel configured to measure a pressure in the unit area and generate apressure reading. A sensor reading computer system is electricallyconnected to the at least one sensel and configured to read a pressurereading from the at least one sensel. The system further comprises atleast one cover having at least one recess disposed in a first side ofthe at least one cover and configured to accept and retain at least oneunit over the at least one unit area. The cover is configured to holdthe at least one unit immediately laterally adjacent to at least aportion of a respective at least one unit retainer and over a portion ofthe at least one sensel. The cover is retained to the device processingboat by the at least one unit retainer. In an embodiment, the at leastone boat comprises two or more boats, and each of the two or more boatshas two or more sensels disposed therein, and the sensor readingcomputer system is connected to each of the two or more sensels on eachof the two or more boats and is configured to read a separate pressurereading from each of the at least two sensels on each of the two or moretwo boats. In an embodiment, the at least one unit retainer is a magnet,and the cover has at least one cover portion formed from a material thatis attracted to a magnetic field. The at least one cover portioncorresponds to at least a portion of the at least one unit retainer. Themagnet of the at least one unit retainer is configured to clamp the atleast one unit with a clamping force between about 450 grams of forceand about 1000 grams of force. The device processing boat furthercomprises a plurality of border retainers disposed in the base andoutside of the unit area. The unit retainers are disposed in an interiorregion of the border retainers, and the cover is configured to alignover and be retained by the plurality of border retainers. In anembodiment, the at least one recess comprises two or more recesses andthe at least one unit retainer extends under at least two of the two ormore recesses. In an embodiment, the at least one unit retainercomprises two or more unit retainers, and wherein at least two of thetwo or more unit retainers extend under a same one of the two or morerecesses. The cover has an opening over the at least one recess andextending from a second side of the cover to the at least one recess.

A method of processing a device according to an embodiment comprisesproviding at least one unit in a corresponding at least one unit area ona top surface of a boat, the boat having at least one unit retainerimmediately laterally adjacent to the at least one unit area, andproviding a cover over the at least one unit, the cover having at leastone recess in a bottom surface of the cover and at least one openingover the at least one recess, the at least one unit extending into theat least one recess, the cover retained to the top surface of the boatby the at least one unit retainer, the cover clamping the at least oneunit to the top surface of the boat. The method further comprisesmounting at least one top package on the at least one unit by aconnector and through the opening, and activating the connector andaffixing the top package to the unit. In an embodiment the unit retaineris a magnet, and the cover has a cover portion that is a ferromagneticmaterial, and the providing the cover comprises attaching the cover tothe boat using a magnetic interaction between the at least one unitretainer and the cover portion. The providing the at least one unitfurther comprises aligning the at least one unit over at least onesensel disposed in the boat and extending under the unit area, and themethod further comprises measuring a clamping pressure at the senselwith a sensor reading computer system. In an embodiment, the coverclamps the at least one unit to the boat with a clamping force betweenabout 450 grams of force and about 1000 grams of force.

In a representative embodiment, a device processing system includes atleast one device processing boat comprising: a base; at least one unitretainer disposed in the base and having a portion immediately adjacentto a unit area; at least one pressure sensor disposed on the base andhaving at least one sensel extending into the unit area, the at leastone sensel configured to measure a pressure in the unit area andgenerate a pressure reading; and a sensor reading computer systemelectrically connected to the at least one sensel and configured to reada pressure reading from the at least one sensel. The at least one deviceprocessing boat may comprise two or more boats, with each of the two ormore boats having at least two sensels disposed therein. The sensorreading computer system may be connected to each of the at least twosensels on each of the two or more boats. The sensor reading computersystem may be configured to read separate pressure readings from each ofthe at least two sensels on each of the two or more boats. At least onecover may have at least one recess disposed in a first side of the coverand may be configured to accept and retain at least one unit over theunit area, and may be configured to hold the at least one unitimmediately laterally adjacent to at least a portion of a respective atleast one unit retainer and over a portion of the at least one sensel.The cover may be retained to the device processing boat by the at leastone unit retainer. The at least one unit retainer may be a magnet,wherein the cover has at least one cover portion formed from a materialthat is attracted to a magnetic field. The at least one cover portionmay correspond to at least a portion of the at least one unit retainerand the magnet of the at least one unit retainer may be configured toclamp the at least one unit with a clamping force between about 450grams of force and about 1000 grams of force. The device processing boatmay further comprise a plurality of border retainers disposed in thebase and outside of the unit area, wherein the unit retainers may bedisposed in an interior region of the border retainers, and the covermay be configured to align over and be retained by the plurality ofborder retainers. The cover may have an opening over the at least onerecess and extending from a second side of the cover to the at least onerecess. The at least one recess may comprise two or more recesses, andthe at least one unit retainer may extend under at least two of the twoor more recesses. The at least one unit retainer may comprise two ormore unit retainers, and at least two of the two or more unit retainersmay extend under a same one of the two or more recesses.

In another representative embodiment, a device processing systemincludes at least one device processing boat comprising: a base; atleast one unit retainer disposed in the base and having a portionimmediately adjacent to a unit area; at least one pressure sensordisposed on the base and having at least one sensel extending into theunit area (the at least one sensel configured to measure a pressure inthe unit area and generate a pressure reading); and at least one coverhaving at least one recess disposed in a first side of the at least onecover and configured to accept and retain at least one unit over theunit area, and configured to hold the at least one unit immediatelylaterally adjacent to at least a portion of a respective at least oneunit retainer and over a portion of the at least one sensel. The deviceprocessing system may further comprise a sensor reading computer systemelectrically connected to the at least one sensel and may be configuredto read a pressure reading from the at least one sensel. The at leastone device processing boat may comprise two or more boats, and whereineach of the two or more boats may have at least two sensels disposedtherein, wherein the sensor reading computer system may be connected toeach of the at least two sensels on each of the two or more boats andthe sensor reading computer system may be configured to read a separatepressure reading from each of the at least two sensels on each of thetwo or more boats. The cover may be retained to the device processingboat by the at least one unit retainer having a surface substantiallylevel with a surface of a first portion of the at least one unitretainer. The at least one unit retainer may be a magnet, and the covermay have at least one cover portion formed from a material that isattracted to a magnetic field, wherein the at least one cover portioncorresponds to at least a portion of the at least one unit retainer andwherein the magnet of the at least one unit retainer is configured toclamp the at least one unit with a clamping force between about 450grams of force and about 1000 grams of force. The device processing boatmay further comprise a plurality of border retainers disposed in thebase and outside of the unit area, wherein the unit retainers may bedisposed in an interior region of the border retainers, and wherein thecover may be configured to align over and be retained by the pluralityof border retainers. The cover may have an opening over the at least onerecess and extending from a second side of the cover to the at least onerecess. The at least one recess may comprise two or more recesses,wherein the at least one unit retainer extends under at least two of thetwo or more recesses. The at least one unit retainer may comprise two ormore unit retainers, wherein at least two of the two or more unitretainers extend under a same one of the two or more recesses.

In yet another representative embodiment, a method of processing adevice comprises: providing at least one unit in a corresponding atleast one unit area on a top surface of a boat, the boat having at leastone unit retainer immediately laterally adjacent to the corresponding atleast one unit area; providing a cover over the at least one unit, thecover having at least one recess in a bottom surface of the cover and atleast one opening over the at least one recess, the at least one unitextending into the at least one recess, the cover retained to the topsurface of the boat by the at least one unit retainer, the coverclamping the at least one unit to the top surface of the boat; mountingat least one top package on the at least one unit by a connector andthrough the at least one opening; and activating the connector andaffixing the top package to the unit. The step of providing the covermay further comprise: the unit retainer comprising a magnet; a coverportion of the cover comprising a ferromagnetic material; and attachingthe cover to the boat using a magnetic interaction between the at leastone unit retainer and the cover portion. The step of providing the atleast one unit may further comprise aligning the at least one unit overat least one sensel disposed in the boat and extending under the unitarea. The method may further comprise measuring a clamping pressure atthe sensel with a sensor reading computer system. The step of providingthe cover may comprise the cover clamping the at least one unit to theboat with a clamping force between about 450 grams of force and about1000 grams of force.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A device processing system comprising: at leastone device processing boat comprising: a base; at least one unitretainer disposed in the base and having a portion immediately adjacentto a unit area; and at least one pressure sensor disposed on the baseand having at least one sensel extending into the unit area, the atleast one sensel configured to measure a pressure in the unit area andgenerate a pressure reading; and a sensor reading computer systemelectrically connected to the at least one sensel and configured to reada pressure reading from the at least one sensel.
 2. The deviceprocessing system of claim 1, wherein the at least one device processingboat comprises two or more boats, and wherein each of the two or moreboats has at least two sensels disposed therein, and wherein the sensorreading computer system is connected to each of the at least two senselson each of the two or more boats and wherein the sensor reading computersystem is configured to read a separate pressure reading from each ofthe at least two sensels on each of the two or more boats.
 3. The deviceprocessing system of claim 1, further comprising: at least one coverhaving at least one recess disposed in a first side of the at least onecover and configured to accept and retain at least one unit over theunit area, and configured to hold the at least one unit immediatelylaterally adjacent to at least a portion of a respective at least oneunit retainer and over a portion of the at least one sensel; and whereinthe cover is retained to the device processing boat by the at least oneunit retainer.
 4. The device processing system of claim 3, wherein theat least one unit retainer is a magnet, and wherein the cover has atleast one cover portion formed from a material that is attracted to amagnetic field, the at least one cover portion corresponding to at leasta portion of the at least one unit retainer and wherein the magnet ofthe at least one unit retainer is configured to clamp the at least oneunit with a clamping force between about 450 grams of force and about1000 grams of force.
 5. The device processing system of claim 3, whereinthe device processing boat further comprises a plurality of borderretainers disposed in the base and outside of the unit area, wherein theat least one unit retainer is disposed in an interior region of theborder retainers, and wherein the cover is configured to align over andbe retained by the plurality of border retainers.
 6. The deviceprocessing system of claim 3, wherein the cover has an opening over theat least one recess and extending from a second side of the cover to theat least one recess.
 7. The device processing system of claim 3, whereinthe at least one recess comprises two or more recesses and wherein theat least one unit retainer extends under at least two of the two or morerecesses.
 8. The device processing system of claim 7, wherein the atleast one unit retainer comprises two or more unit retainers, andwherein at least two of the two or more unit retainers extend under asame one of the two or more recesses.
 9. A device processing systemcomprising: at least one device processing boat comprising: a base; atleast one unit retainer disposed in the base and having a portionimmediately adjacent to a unit area; at least one pressure sensordisposed on the base and having at least one sensel extending into theunit area, the at least one sensel configured to measure a pressure inthe unit area and generate a pressure reading; and at least one coverhaving at least one recess disposed in a first side of the at least onecover and configured to accept and retain at least one unit over theunit area, and configured to hold the at least one unit immediatelylaterally adjacent to at least a portion of a respective at least oneunit retainer and over a portion of the at least one sensel.
 10. Thedevice processing system of claim 9, further comprising: a sensorreading computer system electrically connected to the at least onesensel and configured to read a pressure reading from the at least onesensel.
 11. The device processing system of claim 10, wherein the atleast one device processing boat comprises two or more boats, andwherein each of the two or more boats has at least two sensels disposedtherein, and wherein the sensor reading computer system is connected toeach of the at least two sensels on each of the two or more boats andwherein the sensor reading computer system is configured to read aseparate pressure reading from each of the at least two sensels on eachof the two or more boats.
 12. The device processing system of claim 10,wherein the cover is retained to the device processing boat by the atleast one unit retainer having a surface substantially level with asurface of the device processing boat.
 13. The device processing systemof claim 12, wherein the at least one unit retainer is a magnet, andwherein the cover has at least one cover portion formed from a materialthat is attracted to a magnetic field, the at least one cover portioncorresponding to at least a portion of the at least one unit retainerand wherein the magnet of the at least one unit retainer is configuredto clamp the at least one unit with a clamping force between about 450grams of force and about 1000 grams of force.
 14. The device processingsystem of claim 9, wherein the device processing boat further comprisesa plurality of border retainers disposed in the base and outside of theunit area, wherein the at least one unit retainer is disposed in aninterior region of the border retainers, and wherein the cover isconfigured to align over and be retained by the plurality of borderretainers.
 15. The device processing system of claim 9, wherein thecover has an opening over the at least one recess and extending from asecond side of the cover to the at least one recess.
 16. The deviceprocessing system of claim 9, wherein: the at least one recess comprisestwo or more recesses and wherein the at least one unit retainer extendsunder at least two of the two or more recesses; and the at least oneunit retainer comprises two or more unit retainers, and wherein at leasttwo of the two or more unit retainers extend under a same one of the twoor more recesses.
 17. A system for processing semiconductor units, thesystem comprising: a device processing boat comprising: a base; aplurality of unit retainers on a first side of the base; a plurality ofsensels on a second side of the base opposing the first side, each ofthe plurality of sensels configured to measure a pressure exertedthereon; and a cover attached to the second side of the base, the coverhaving a plurality of recesses extending from a first surface of thecover facing the base to a second surface of the cover facing away fromthe base, each of the plurality of recesses configured to hold asemiconductor unit over a respective one of the plurality of sensels.18. The system of claim 17, wherein each of the plurality of unitretainers has a first portion directly under a respective one of theplurality of sensels, and has a second portion laterally adjacent to therespective one of the plurality of sensels.
 19. The system of claim 17,wherein the cover comprises a plurality of openings in the secondsurface of the cover, each of the plurality of openings exposing arespective one of the plurality of recesses.
 20. The system of claim 17,wherein the plurality of sensels are connected and extend continuouslyover the second side of the base, wherein the system further comprises asensor coupled to the plurality of sensels, and wherein the sensor isconfigured to measure a total pressure exerted on the plurality ofsensels.